Principle 1 Perceivable · Guideline 1.4: Distinguishable
1.4.13 Content on Hover or Focus
Content that appears must stay reachable and must not vanish on its own.
What this means in practice
Applies to tooltips and dropdowns: dismissible with Escape, hoverable so the pointer can move into them, and persistent rather than disappearing after a moment.
Normative wording
The binding text lives at the W3C. What you read here is our own faithful rendering – not a quotation.